[gcc r14-10105] tree-optimization/114832 - wrong dominator info with vect peeling

[gcc r14-10105] tree-optimization/114832 - wrong dominator info with vect peeling

[Richard Biener]

https://gcc.gnu.org/g:e28e8ab1a92e9b49f7c4045377577c8dc17751b7

commit r14-10105-ge28e8ab1a92e9b49f7c4045377577c8dc17751b7
Author: Richard Biener <rguenther@suse.de>
Date:   Wed Apr 24 06:24:22 2024 +0200

    tree-optimization/114832 - wrong dominator info with vect peeling
    
    When we update the dominator of the redirected exit after peeling
    we check whether the immediate dominator was the loop header rather
    than the exit source when we later want to just update it to the
    new source.  The following fixes this oversight.
    
            PR tree-optimization/114832
            * tree-vect-loop-manip.cc (slpeel_tree_duplicate_loop_to_edge_cfg):
            Fix dominance check.
    
            * gcc.dg/vect/pr114832.c: New testcase.

Diff:
---
 gcc/testsuite/gcc.dg/vect/pr114832.c | 13 +++++++++++++
 gcc/tree-vect-loop-manip.cc          |  2 +-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/gcc/testsuite/gcc.dg/vect/pr114832.c b/gcc/testsuite/gcc.dg/vect/pr114832.c
new file mode 100644
index 00000000000..2de07ae22ef
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr114832.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-fno-tree-loop-if-convert -fno-tree-loop-distribute-patterns" } */
+
+int a, b, c, d[3];
+void e() {
+  int f, g = 0;
+  for (; g < 3; g++) {
+    if (f || a || b && c) {
+      int h, *i = &h, **j = &i;
+    }
+    d[g] = 0;
+  }
+}
diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc
index 8d9b533d50f..43c7881c640 100644
--- a/gcc/tree-vect-loop-manip.cc
+++ b/gcc/tree-vect-loop-manip.cc
@@ -1523,7 +1523,7 @@ slpeel_tree_duplicate_loop_to_edge_cfg (class loop *loop, edge loop_exit,
 
   exit_dest = exit->dest;
   was_imm_dom = (get_immediate_dominator (CDI_DOMINATORS,
-					  exit_dest) == loop->header ?
+					  exit_dest) == exit->src ?
 		 true : false);
 
   /* Also copy the pre-header, this avoids jumping through hoops to